Panarctic Flora

342626a Poa hartzii subsp. hartzii

2n= 63-70 70 (9-10x). - Far East (N)?, Greenland. - At least three reports.
The Far East report of 2n = 70 for Poa hartzii s. str. is from Wrangel Island (Petrovsky and Zhukova 1981).

Geography: Asian Beringian? - North American (N) - amphi-Atlantic (W): NOR RFE? CAN GRL.

Notes: Subspecies hartzii is mainly an American-Greenlandic race, in Europe found only in Svalbard amd perhaps not transgressing to northeastern Asia. Tzvelev (PAF proposal) reported Poa hartzii s. str. from Wrangel Island but we are reluctant to accept this report. Specimens should be thoroughly checked as subsp. vrangelica was described from this island. Soreng et al. (2003) and Soreng (2007) did not accept Alaskan records of P. hartzii s. str. and we have seen no specimens supporting it.

Haugen and Elven: Poa hartzii (s. str.) is pollen-sterile and agamospermous (Haugen 2000). Tzvelev (1976) suggested that it could be derived from hybrids between P. glauca and either P. abbreviata or P. arctica. Edmondson (1980) tentatively accepted the former hybrid hypothesis. Investigating the Svalbard plants, Haugen (2000) found no indications in morphology or isoenzymes of an origin involving P. abbreviata or P. arctica (subsp. arctica and subsp. caespitans). An involvement of P. glauca was not excluded by the data. Gillespie et al. (1997) found support for a hybrid origin of Canadian P. hartzii from the circumpolar P. glauca and the North American P. secunda. She has later (in comment) partly revised her opinion but still finds evidence (cpDNA) of its female genome coming from P. glauca and the other part from P. secunda and P. ammophila (see Soreng 2007). Poa hartzii is of hybrid origin but certainly not a recent hybrid in view of its large distribution and comparative uniformity throughout Svalbard, Greenland, and much of the Canadian High Arctic, and its presence far outside the range of some of its assumed parents (P. secunda and P. ammophila).